Method of and apparatus for the processing of meat

ABSTRACT

The water holding capacity of meat is improved by agitating the meat at an alleged temperature with the processing solution and by maintaining the alleged temperature with precision. A preferred temperature is in the range of 45° to 60° F. and the agitation is preferably a massaging action after injection of the liquid into the meat.

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of Provisional Application60/189,667 filed Mar. 15, 2000.

FIELD OF THE INVENTION

[0002] My present invention relates to a method of and to an apparatusfor processing meat wherein the bodies or pieces of meat are contactedwith a treating liquid and the bodies of meat are agitated to distributethe treating liquid in the meat. More particularly, the inventionrelates to the treatment of meat utilizing a massaging of the meatfollowing an injection of a liquid, usually in the form of an aqueoussolution, into the meat.

BACKGROUND OF THE INVENTION

[0003] In U.S. Pat. No. 5,564,332, there is described a paddle massagerin which pieces of meat can be subjected to a massaging action todistribute an aqueous solution, which has been injected into the meat,uniformly throughout the tissue thereof. A prior patent dealing withsuch massaging action is U.S. Pat. No. 5,405,630. A plant utilizing sucha paddle massager and a maceration of the meat product before it entersthe massager is described in U.S. Pat. No. 5,972,398.

[0004] In prior massaging techniques, it has generally been thought thatthe massaging action should be carried out cold, i.e. at a relativelylow temperature which is maintained by circulating a coolant through thejacket of the machine. A typical temperature of this cooling liquid,which is generally a glycol/water solution, can be about 23° F.

[0005] The massaging action is intended to uniformly distribute thetreating solution into the muscle tissue of the meat. The solution canbe a brine and normally includes phosphates, nitrate, nitrite, salt,flavor enhancers, proteins, binders fats or other meat treating agentssuch as preservatives.

[0006] The tradition has been to inject the meat with the solution,usually with needles under an elevated pressure under conditions inwhich the meat is normally cold at the time it is injected and theinjectable solution itself is relatively cold. It is desirable toconduct the massaging action so that the product emerges from themassager in a relatively dry state, i.e. the marinade or treatingsolution is fully taken up within the body of the meat, leaving thesurface free from or practically free from a liquid film.

[0007] These techniques have been used for all sorts of meats, includingbeef, pork, lamb and veal, and for practically any cut of meat in whicha substantial body of meat must be tenderized or treated, for example,roasts, hams, shanks, loins and the like.

[0008] However, earlier systems have been found to involve a number ofproblems. For example, it has been found that, with conventionalsystems, a phenomenon may develop which can impede effective massaging.For example proteins released from the meat tend to bind with water ofthe treatment solution at a given temperature (depending on thecomposition of the treatment solution) and form a compound. Thiscompound may be exuded from the body of the meat and act as an externalcoating or internal barrier. In either case, this compound impairspenetration, absorption and/or dispersion of the treatment solutionthroughout the cross section of the body and the result is anunaesthetic surface. It has been noted, further, that meat productswhich are treated cold following the injection may not develop theuniform internal coloration which is desired for many cuts of meat.Furthermore, the protein/water coating on the body of meat tends toreduce friction and thus the massaging effectiveness so that longermassaging operations may be required.

[0009] Still another drawback of earlier systems appears to be thelimited breakdown of treating solutions like polyphosphates and nitritesby enzymes present in the meat so that such additives to the inject arenot utilized completely or efficiently.

OBJECTS OF THE INVENTION

[0010] It is, therefore, the principal object of the present inventionto provide an improved method of treating or processing meat involvingcontact of a treating liquid with the meat, whereby drawbacks of earliersystems are obviated.

[0011] More specifically, it is an object of this invention to effectthe agitation of meat (e.g. the massaging and/or tumbling) so that theagitation takes place more efficiently, with a better yield, from thepoint of view of the solution used and with higher quality results.

[0012] It is also an object of the invention to provide an improvedapparatus for the treatment of the meat.

SUMMARY OF THE INVENTION

[0013] These objects are attained, in accordance with the invention by amethod which comprises contacting bodies of meat with a treatingsolution; agitating the bodies of meat in contact with the treatmentsolution at an elevated temperature until the bodies of meat aresubstantially dry; and recovering the bodies of meat in a substantiallydry state. I have found that the elevated temperature should be in therange of 45° F. to 60° F.

[0014] More particularly the method can comprise the steps of:

[0015] (a) contacting bodies of meat with a treating solution;

[0016] (b) heating the bodies of meat in contact with the treatingsolution in an agitator to a predetermined elevated temperature andmaintaining the temperature substantially constant while agitating themeat for a period of time sufficient to distribute the treating solutionin the meat;

[0017] (c) thereafter cooling the bodies of meat in the agitator whilecontinuing to agitate the meat; and

[0018] (d) recovering the bodies of meat in a substantially dry statefrom the agitator.

[0019] While within the broad concepts of my invention, any type ofagitator can be used, the preferred agitator is a massager or tumbler.Similarly, my invention contemplates contacting the meat with the liquidin any suitable fashion, but injection at a lower temperature than theelevated temperature mentioned is preferred.

[0020] Thus, according to the invention, the bodies of meat can becontacted with the treating solution by injecting the bodies of meatwith an inject at a temperature less than the elevated temperature andthe agitator is preferably a rotary paddle massager or a tumbler. Theelevated temperature is preferably between substantially 45° F. and 60°F., the temperature less than the elevated temperature is substantially15° to 40° F. below the elevated temperature and the meat is cooled by15° to 40° F. below the elevated temperature in step (c).

[0021] An important aspect of the invention is the control of thetemperature at which the agitation takes place. I have found that, inthe past, because of different temperatures of the bodies of meat fromearlier stages, different temperatures of the liquids used and, ingeneral, the high variability at which processing occurred, the resultswere highly unpredictable, not reproducible and often unsatisfactory.When the elevated temperature of the present invention is used and thattemperature is controlled to, say, ±2° F., problems are eliminated andexcellent meat qualities with high and reproducible water holdingcapacity are obtained.

[0022] The elevated temperature is controlled in step (b) by measuringdirectly a temperature of the bodies of meat in the agitator andregulating a temperature of the agitator in response to the measuredtemperature.

[0023] The temperature of the bodies of meat in the agitator can bemeasured for example by causing the bodies of meat to contact directly atemperature sensor mounted in a wall of the agitator. Alternatively thetemperature of the bodies of meat in the agitator can be measured byinserting a temperature measuring sensor into bodies of meat in theagitator.

[0024] The bodies of meat can be selectively heated and cooled in theagitator by selectively passing a heated or cooled fluid through ajacket thereof.

[0025] According to another feature of the invention an apparatus forprocessing meat can comprise a vessel for receiving bodies of meat incontact with a treating liquid and for agitating the bodies of meat todistribute the treating liquid in the bodies of meat, and means forselectively heating and cooling the vessel during the agitation of thebodies of meat therein. Preferably the vessel has a jacket and the meansfor selectively heating and cooling the vessel comprises a refrigerationunit for circulating a cooling liquid through the jacket and a heaterfor passing a heating liquid through the jacket. A temperature sensorcan be positioned for direct contact with bodies of meat in the vesseland operatively connected to the means for selectively heating andcooling the vessel for controlling a temperature of the vessel duringthe agitation of the bodies of meat therein. For instance thetemperature sensor can extend through a wall of the vessel and can bethermally insulated therefrom to respond directly to a surfacetemperature of bodies of meat in the vessel. Alternatively, thetemperature sensor is provided with a member capable of being thrustinto the vessel to pierce a body of meat therein. In the latter case,this member can have a plurality of sensing regions along a lengththereof for providing an average temperature of the body of meat througha thickness thereof.

[0026] When a massager is used it is advantageous to control themassaging operation at least in the first stages in response to ameasured temperature of a body of meat in the massager. For thatpurpose, the surface temperature can be measured and the heating andcooling liquid fed through the jacket can be controlled in response tothat temperature so that should the temperature rise the heating liquidsupply can be cut-off until the temperature falls by transfer of heat tothe interior of the body of meat or a cooling flow of liquid to thejacket can be initiated.

[0027] It has been found to be more advantageous, however, to provide aprobe having a plurality of spaced apart sensors and to insert thatprobe into a body of meat within the massager after *the latter has beenbrought to standstill and to use the higher temperature of thosemeasured in the case or the body is to be cooled or the lowertemperature of those measured in the case where the body is to be heatedas an indication of the internal temperature of the piece of meat wherean average may not be a desirable basis for control.

[0028] According to another feature of the invention the massager has ajacket through which a temperature-control liquid is circulated, and thetemperature-control liquid is initially heated and then cooled insuccessive steps.

[0029] Alternatively, the massager can have a jacket through which atemperature-control liquid is circulated, the method further comprisingthe steps of separately heating and cooling portions of thetemperature-control liquid, feeding heated temperature-control liquidthrough the jacket during the heating step, and then rapidly coolingbodies of meat by switching the jacket to receive a cooled portion ofthe temperature-control liquid.

[0030] A preferred apparatus according to the invention can comprise:

[0031] a support;

[0032] a drum on the support for receiving bodies of meat injected withan aqueous solution, for retaining the bodies of meat for massaging ofthe solution into the meat, and for discharging massaged bodies of meat;

[0033] means rotatable at a variable number of rotations per minute formassaging the bodies of meat in the drum;

[0034] a temperature-control jacket on the drum; and

[0035] means for selectively circulating a heated and a cooled liquidthrough the jacket to selectively heat and cool the bodies of meatduring the massaging thereof.

[0036] The programming means for the massager is connectable to therotatable means and the means for selectively circulating forprogramming the apparatus to:

[0037] raise a temperature of the bodies of meat to a relatively hightemperature while massaging the bodies of meat at a certain rate ofspeed of the rotatable means,

[0038] maintain the bodies of meat at the relatively high temperaturefor a predetermined time period while continuing to massage the aqueoussolution into the meat for a certain time period,

[0039] cool the bodies of meat to a temperature substantially below therelatively high temperature while continuing to massage the aqueoussolution into the meat at a certain rate of speed of the rotatablemeans, and

[0040] maintain the bodies of meat at the temperature below therelatively high temperature for a certain time period while continuingto massage the aqueous solution into the meat for a certain period.

[0041] One of the major advantages of the present invention is thatholding the meat at a higher temperature than is typically used resultsin a more rapid, thorough and equal (uniform) distribution of the liquidwithin the meat and substantially reduced formation of a protein/waterfilm on the surface of the meat. Furthermore, the increased temperatureof massaging at the initial stage tends to promote the breakdown ofingredients or additives such as polyphosphates and nitrate by enzymesin the meat and hence a greater effectiveness of these components of thetreating solution with a more uniform product especially a deeper andmore uniform coloration. Because the body of meat is free from thefriction reducing film, massaging can be completed more rapidly.Massaging is completed more efficiently, even when the temperature isreduced in the subsequent stage massaging; problems with enzyme coatingof the meat do not arise. The product is obtained in a practically drystage.

BRIEF DESCRIPTION OF THE DRAWING

[0042] The above and other objects, features, and advantages will becomemore readily apparent from the following description, reference beingmade to the accompanying drawing in which:

[0043]FIG. 1 is a cross sectional view of a massaging drum according tothe invention equipped to carry out the processing of this invention;

[0044]FIG. 2 is a detailed cross sectional view of a temperaturemeasurement assembly for the massager;

[0045]FIG. 3 is a cross sectional view of another temperature measuringdevice for use with the present invention;

[0046]FIG. 4 is a detail of the temperature prove thereof; and

[0047]FIG. 5 is a flow diagram illustrating the example.

SPECIFIC DESCRIPTION

[0048] While I have mentioned that the method of the invention can bepracticed with any type of agitator and that the bodies of meat whichare processed can be contacted with the treating liquid, which can beany liquid which is to be distributed in the meat, preferably I use amassager of the type marketed by WTI Inc. under the name Polar Massagerand which can have a construction similar to that shown in FIG. 1.

[0049] The liquid is assumed to have been previously injected into themeat. The polar massager 10 can be mounted on a support represented onlydiagrammatically at 11 and can comprise a stationary massager drum 12with an inlet shoot 13 for the pieces of meat and an outlet shoot 14from which the meat is discharged.

[0050] Within the drum 12, there are a number of paddles 15 mounted on ashaft 16 rotated by a drive 17 which can be controlled by theprogrammable computer 18 so that the torque, speed and variationsthereof are controlled by the processing program. The drum or tank 12has a jacket 20 which can be connected to a refrigeration systemrepresented diagrammatically at 21 or to a heater 22 so that heated orchilled liquid is circulated through the jacket and the temperature ofthe meat is raised or lowered as it is processed in the massager.

[0051] A key to the method of the invention is that the elevatedtemperature at which the massaging is effected is maintained withconsiderable accuracy, say to ±2° C. and that is achieved, in accordancewith one embodiment of the invention by contacting the bodies of meatwithin the massager directly with a temperature sensor. For thatpurpose, the temperature sensor 22 is mounted in a wall of the drum ortank in a position in which it is contacted by the bodies of meat asthey are massaged.

[0052] As can be seen from FIG. 2, the temperature sensor 22 has asensing element 23 for contact with the service of the meat in thevessel and is surrounded by an insulating bushing 24 so that the walltemperature of the vessel will not effect the reading. The insulatorbushing 24 can be affixed in the tank shell 12 by a mounting sleeve 25.The output cable 26 can be connected to the computer 18. The latter maysurface a number of massagers and even other equipment utilized withsuch massagers such as the injectors or conveyors or the like and, ofcourse, the temperature control system 21, 22. The computer 18 may inturn be connected to the computer terminals 30 by conventionalnetworking.

[0053] As has been described, once the bodies of meat carrying theliquid are introduced into the massager, they are brought to an elevatedtemperature in the range of 45° F. to 60° F. and massaged until theliquid is fully absorbed. The heating of the massager is effected viathe circulating liquid utilizing the heater 22, appropriate pumps 31, 32and valves 33, 34 being provided so that selectively hot or cold liquidcan be passed through the jacket of the vessel.

[0054] Once the massaging has been completed, usually in a period of 5minutes to say an hour and a half, the meat can be chilled in themassager and discharged. The temperature control by sensor 22 permitsthe meat to be reproducibly discharged always at the same temperaturewhich is a significant advantage.

[0055] In FIG. 3, I have shown another temperature probe 40 which can bemounted in the wall of the tank or drum and which has a temperaturesensing needle 41 attached to be driven by a piston 42 into bodies ofmeat in the tank. For that purpose, the piston 22 is slidable in acylinder 43 and a pressurizing fluid can be fed through either of theports 44 or 45 to displace the piston 42 to the left or to the rightwithin the cylinder 43 which is mounted by the bushings 46 and 47 on thetank wall. The needle 41 can have a tip sensor 48 and segmental sensors49, 50, 51 etc. enabling the temperatures to be obtained from variousdepths within the body of the meat pierced by the needle. The computer18 can respond to an average temperature or to temperatures measuredclose to the surface or deep within the body of meat as may be desired.To utilize the sensor of FIGS. 3 and 4, the paddles are brought tostandstill.

EXAMPLE

[0056] Evaluation Effects of Hot and Cold Massaging on Product Quality

[0057] A mixture of lean pork leg (fresh ham) muscles (inside andoutside), 5% port fat and curing ingredients were massaged at 32° F. and55° F. Ham samples massaged at 55° F. had higher water holding capacity,firmer structure and better nitrite diffusion.

Materials and Methods

[0058] Lean pork leg (fresh ham) muscles (inside and outside) groundthrough kidney plate, pork fat ground through ⅛ inch plate and curingingredients were obtained from the Meat Processing Laboratories atKansas State University. Meat samples and fat were divided into twoequal parts. First part was incubated at 32° F. and second part wasincubated at 55° F. for 24 hr. Distilled water samples were incubated at32 and 55° F. to make 12% pickle solution at corresponding temperatures.

[0059] Equal amount of inside and outside muscles 5% pork fat, water anddry curing ingredients were measured (Table 1). Massaging of eachtreatment was performed as shown in the flow diagram (FIG. 5). Aftercompletion of massaging, water holding capacity TABLE 1 Curingingredients Ingredients Amount in meat block Water   12% Salt (sodiumchloride)  2.0% Sugar (dextrose)  0.7% Phosphate (sodiumtripolyphosphate)  0.4% Sodium erythorbate 0.055% Sodium nitrite 0.015%

[0060] (WHC), textural properties and nitrite analysis were determined.The WHC of the samples were measured as described in the procedure ofGrau and Hamm (1953). The meat sample (500 mg) was placed on Whatman No.1 filter paper (15 cm diameter) humidified above saturated potassiumchloride solution for 24 hr. Plexiglass plates (15 cm²) were placedon/under the filter paper and pressed at 5,000 psi for 5 minutes. TheWHC of samples were expressed as the ratio of total area to meat filmarea. The total and meat film areas were calculated using OPTIMAS™ imageanalysis program (Optimas Corporation, Bothell, Wash.). The textureprofiles of the samples, firmness and resiliency, were measured using aTA.XT2 Texture Analyzer version 5.16 (Stable Micro System, Scarsdale,N.Y.). To determine the amount and/or diffusion of nitrite in themuscles, meat samples were taken from the geometrical center of themuscle pieces. Nitrite analysis of these samples were performed usingthe USDA nitrite analysis method for meat samples.

Results and Discussion

[0061] Water holding capacity was defined as the ratio of the total areato meat film area. A larger ratio represents a lower WHC. The samplesmassaged at 55° F. showed a higher WHC with a ratio of 1.58 while thesamples massaged at 32° F. showed a lower WHC with a ratio of 1.98.Interpretation of texture profiles of the samples showed that thesamples massaged at 55° F. had firmer texture (2664.48 g force) comparedto the samples massaged at 32° F. (1677.48 g force). Nitrite analysisshowed that the samples massaged at 55° F. had 46.67 ppm sodium nitritewhile the samples massaged at 32° F. had 40 ppm sodium nitrite.

[0062] Results indicated that massaging action carried out at 55° F.resulted in higher water holding capacity, firmer structure and betterdiffusion of sodium nitrite compared to massaging action carried out at32° F.

I claim:
 1. A method of processing meat which comprises the steps ofcontacting bodies of meat with a treating solution; agitating saidbodies of meat in contact with said treatment solution at a temperatureof substantially 45° F. to 60° F. until said bodies of meat aresubstantially dry; and recovering said bodies of meat in a substantiallydry state.
 2. A method of processing meat comprising the steps of: (a)contacting bodies of meat with a treating solution; (b) heating saidbodies of meat in contact with said treating solution in an agitator toa predetermined elevated temperature and maintaining said temperaturesubstantially constant while agitating said meat for a period of timesufficient to distribute the treating solution in the meat; (c)thereafter cooling the bodies of meat in said agitator while continuingto agitate the meat; and (d) recovering said bodies of meat in asubstantially dry state from said agitator.
 3. The method defined inclaim 2 wherein said bodies of meat are contacted with said treatingsolution by injecting said bodies of meat with an inject at atemperature less than said elevated temperature and said agitator is arotary paddle massager or a tumbler.
 4. The method defined in claim 3wherein said elevated temperature is between substantially 45° F. and60° F., said temperature less than said elevated temperature issubstantially 15° to 40° F. below said elevated temperature and the meatis cooled by 15° to 40° F. below said elevated temperature in step (c).5. The method defined in claim 2 wherein said elevated temperature iscontrolled in step (b) by measuring directly a temperature of the bodiesof meat in said agitator and regulating a temperature of said agitatorin response to the measured temperature.
 6. The method defined in claim5 wherein said temperature of the bodies of meat in said agitator ismeasured by causing said bodies of meat to contact directly atemperature sensor mounted in a wall of the agitator.
 7. The methoddefined in claim 5 wherein said temperature of the bodies of meat insaid agitator is measured by inserting a temperature measuring sensorinto bodies of meat in said agitator.
 8. The method defined in claim 2wherein said bodies of meat are selectively heated and cooled in saidagitator by selectively passing a heated or cooled fluid through ajacket thereof.
 9. A method processing meat which comprises the steps ofcontacting bodies of meat with a treating solution; agitating saidbodies of meat in contact with said treatment solution at apredetermined temperature until said bodies of meat are substantiallydry while controlling said temperature within ±2° F.; and recoveringsaid bodies of meat in a substantially dry state.
 10. The method definedin claim 9 wherein said temperature is controlled by measuring directlya temperature of the bodies of meat during agitation thereof by contactof a sensor with the bodies of meat, and regulating a temperature of avessel in which said bodies of meat are agitated in response to themeasured temperature.
 11. An apparatus for processing meat whichcomprises: a vessel for receiving bodies of meat in contact with atreating liquid and for agitating said bodies of meat to distribute saidtreating liquid in said bodies of meat; and means for selectivelyheating and cooling said vessel during the agitation of said bodies ofmeat therein.
 12. The apparatus defined in claim 11 wherein said vesselhas a jacket, said means for selectively heating an cooling said vesselcomprising a refrigeration unit for circulating a cooling liquid throughsaid jacket and a heater for passing a heating liquid through saidjacket.
 13. The apparatus defined in claim 11, further comprising atemperature sensor positioned for direct contact with bodies of meat insaid vessel and operatively connected to said means for selectivelyheating and cooling said vessel for controlling a temperature of saidvessel during the agitation of said bodies of meat therein.
 14. Theapparatus defined in claim 13 wherein said temperature sensor extendsthrough a wall of said vessel and is thermally insulated therefrom torespond directly to a surface temperature of bodies of meat in saidvessel.
 15. The apparatus defined in claim 13 wherein said temperaturesensor is provided with a member capable of being thrust into saidvessel to pierce a body of meat therein.
 16. The apparatus defined inclaim 15 wherein said member has a plurality of sensing regions along alength thereof for providing an average temperature of the body of meatpierced thereby.
 17. The apparatus defined in claim 11 wherein saidvessel is a massager having a massaging drum formed with a temperaturecontrol jacket and a rotary paddle in said drum, said means forselectively heating and cooling said vessel including means forselectively circulating a heated and a cooled liquid through saidjacket, said apparatus further comprising programming means for raisinga temperature of said bodies of meat in said massaging drum to apredetermined elevated temperature while massaging said bodies of meatwith a controlled torque of said rotary paddle.
 18. The apparatusdefined in claim 17, further comprising a temperature sensor positionedfor direct contact with bodies of meat in said massaging drum andoperatively connected to said means for selectively circulating saidheated and a cooled liquid through said jacket for controlling atemperature of said massaging drum during the agitation of said bodiesof meat therein.
 19. The apparatus defined in claim 18 wherein saidtemperature sensor extends through a wall of said massaging drum and isthermally insulated therefrom to respond directly to a surfacetemperature of bodies of meat in said massaging drum.
 20. The apparatusdefined in claim 18 wherein said temperature sensor is provided with amember capable of being thrust into an interior of said massaging drumto pierce a body of meat therein.